Idiopathic bone marrow failure states and cytopenias (IBMFS&C) are rare disorders characterized by hematopoietic progenitor or stem cell failure resulting in deficient production of one, or all, blood cell lineages. Immune pathophysiology is a unifying factor in many cases of all these diseases. Prior collaborative trials have led to the improvement of effective medical therapy for aplastic anemia (AA), but ongoing multi-center studies are required to advance further the outcome for AA and especially the other bone IBMFS for which few useful treatment options exist. Here, we propose formation of the IBMFS&C Rare Disease Clinical Research Center (RDCRC) at The Cleveland Clinic Foundation (CCF) Cancer Center, encompassing a consortium of several specialized centers, patient advocacy group, and data and a collaboration with a data technology coordinating center (DTCC). The IBMFS&C RDCRC will focus on AA, paroxysmal nocturnal hemoglobinuria, single-lineage cytopenias including large granular lymphocyte leukemia and pure red cell aplasia, and various myelodysplastic syndromes. This application presents a multi-targeted approach to improving the medical therapy for IBMFS&C that includes: 1) implementing treatment algorithms for each IBMFS that define standards of care, 2) systematically evaluating novel laboratory assays that may improve the diagnostic accuracy or understanding of pathophysiologic mechanisms, 3) enrolling patients into a longitudinal follow-up study to correlate new and established diagnostic variables with outcome, 4) comparing medical and transplant approaches for each relevant disorder, 5) developing experimental treatment protocols for disease subsets currently without good treatment options or without a standard treatment approach, 6) training of post-doctoral fellows to develop clinical trials and translational research projects for the IBMFS&C, 7) educating community physicians in the diagnosis and management of the IBMFS&C, and 8) improving outreach, education and referral resources for patients and physicians, in collaboration with the Aplastic Anemia & MDS International Foundation (AAMDSIF). Due to the expertise of the PI, together with the experience and size of CCF CC, CCF uniquely is positioned to serve as an RDCRC in IBMFS&C. A number of leading experts formed a consortium of medical centers that will be an integral part of the RDCRC. To support further its activities, additional infrastructure for this effort will include a formation of a rare disease office in each of the centers of the consortium, specialized laboratory testing sites, oversight of clinical trials, data management by the DTCC, and patient referral and education by the AAMDSIF. The IBMFS&C RDCRC and the consortium have developed a plan for educating fellows and community physicians about IBMFS&C. The success of these efforts will be evaluated in part by tracking referrals to the participating centers for standard treatment, or enrollment in the longitudinal and treatment protocols.